"Mel B is spearheading the crusade for the band to do a reunion tour as they had a total blast performing at the closing ceremony," a source said. "Geri Halliwell, Mel C and Emma Bunton are all on board, but, of course, the lone holdout is Victoria.

"Vicky says she just has way too much on her plate right now with her fashion label and so busy being a mother to four young children, and wife to David and it just doesn't seem like she wants any part of a reunion tour.

"Mel B is the mama bear and de facto leader of the Spice Girls and it's no secret that she and Vicky have had their differences over the years.

"However, Mel has been extremely diplomatic and sincere when talking to Vicky about doing the reunion tour and is hopeful that she will relent and agree to do it.

"Mel B is very persuasive and always gets what she wants and she has appealed to the fact that Vicky now has a daughter. Mel told Vicky it's time to show little Harper what girl power is really all about!"

Mel B apparently wants to do a short tour of major worldwide cities like Los Angeles, New York City and London to coincide with the premiere of the Spice Girls musical Viva Forever.

The Spice Girls were apparently prepared to perform without Beckham at the closing ceremony, but Posh Spice changed her mind when she realized this, with a source saying she thought "it would look really bad" if she was absent.